There are known several medicinal agents like Pyracetam, Aminalon, Pyriditol, Pantogam, Sodium Oxybutyrate, etc. (1) stimulating redox processes, enhancing glucose utilisation and improving regional blood flow in the cerebral tissues. The said effects result in the enhanced resistance of neurones to hypoxia.
Shortcoming of these agents is that they only stimulate the synthesis of neurotropic factors but do not possess any neurotropic activity in themselves (2). These agents are not free of side effects and contraindications. Inasmuch as potentialities for intracellular biosynthesis in altered neurones are not substantial the stimulation of regeneration by means of introducing natural neurotropic factors appears to be more expedient.
There is also known Cerebrolysin—a non-protein cerebral hydrolysate comprising free amino acids and low-molecular peptides (3). The said agent increases the efficacy of aerobic energy metabolism, improves intracellular protein synthesis, reveals neuroprotective and neurotropic activity and exerts a positive effect in case of cognitive alterations.
Shortcoming of the said agent is that its neurotropic effects are less potent than those of the natural neurotropic factors. The drug administration does not provide considerable restoration of the anatomical structure and functional activity in damaged cerebral and spinal neurones (4, 5, 6). Cerebrolysin application may entail side effects. Moreover, acute renal failure is a contraindication for the said agent.
There are known neurotropic factors that are low-molecular proteins (15–30 kDa) synthesised by the cell elements of the central nervous system: neurone growth factor, cerebral derivative neurotropic factor, 3-, 4- and 5-neurotrophins, basic and acid fibroblast growth factors, epidermal growth factor, astrocyte factor—S-100 protein, lipoprotein (7, 8). Introduction of the said agents in low doses into neurone cultures provides cell functioning, enables formation and growth of axons via stimulation of RNA, DNA, and protein biosynthesis. Neurotropic factors are necessary both for the survival and differentiation of neurones during embryogenesis and for the maintenance of morphologic and functional properties of mature cells. However, it has been proven in the studies that their efficacy is limited to only neuroprotective activity and the neurotropic effects are manifested at later stages. Endogenous peptide substances in the central nervous system are known to be signal transducers in interneurone or neuroeffector transmission and can function as neurohormones, neurotransmitters or neuromodulators (9, 10, 11). These endogenous substances, neuropeptides, are released from communicational neuronal elements so that a target structure recognises them as information. Neuropeptides have been found to be means of integral modulation of the CNS functions such as reparative processes, memory, motional activity, sensations of pain and pleasure, etc.
There are known peptides Cortexin and Epithalamin extracted from the cattle brain (molecular weight—10 kDa) and capable of supporting structural and functional homeostasis of cell populations secreting these peptides (12, 13).
The present application distinguishes itself from the prior art publications by a new amino sequence L-Ala-L-Glu-L-Asp-L-Pro and is created to solve the problem of obtaining new peptides with neurone functional stimulating activity.